Quantum Computers and Cryptography

About the 2014 talk

Three excursions into quantum computation. From Robert's abstract: “The field of quantum computation started in the 1980s with philosophy-minded people asking questions like: if quantum mechanics is the fundamental theory of the physical world, then shouldn't it also affect the theory of computation? Then, in 1994 came an enormous breakthrough: Peter Shor figured out an efficient quantum algorithm to decompose large integer numbers into their prime factors. The potential implications are not philosophical at all: Shor's algorithm breaks the cryptography system RSA, which is in widest use today for encrypting email and protecting credit card transactions.”

“It's pretty rugged and uncharted territory still, and I would like to take you on three excursions into this wild land: (i) the circuit model of quantum computation, leading up to Shor's algorithm; (ii) a different model, the adiabatic model — as many of you know, a Burnaby-based company, D-Wave, is dedicated to building such a device; and (iii) quantum error-correction — quantum computations need to be protected from decoherence, and I give you a glimpse into how this is done.” In Ray's words: “He has the rare skill of being able to speak about a complex subject so that the rest of us can understand and appreciate it.” Robert returned in October 2025 for a second session, on quantum computers and cryptography.